| 摘要 |
[PROBLEMS] To provide an optical element in which optical characteristics are enhanced by making the optical element have two properties, i.e., oxidation resistance and absorbability of non-exposure light, at the same time. [MEANS FOR SOLVING PROBLEMS] A protective layer (30) is formed while varying the composition in the depth direction, and includes an interface side layer (31) provided on a thin film layer (L1), i.e., the outermost layer of a multilayer film (20), a surface side layer (32) provided on the inter face side layer (31) as the outermost surface of an optical element (100), and an intermediate layer (33). The interface side layer (31) has such properties as absorbing non-exposure light from a light source relatively. The surface side layer (32) suppresses oxidation of the surface of the multilayer film (20). Consequently, deterioration of reflectance on the surface of the optical element (100) can be suppressed while reducing reflection of the non-exposure light, even if extreme UV-rays are radiated in the exposure device. |
